Turnbarrel connection



Aug. 16, 1949.

R. w. LANDN TURNBARREL CONNECTION Filed Jan. 17, 1947 Gttorrleg Patented Aug. 16, 1949 UNITED STATES rATENT y OFFICE 2,479,172 TURNBARREL CONNECTION Robert W.` Landon,` Roscoe, Calif. Application January 17, 1947, Serial No. 722,739

The present invention relates to turnbuckle connections in general and particularly to means to prevent unintended separation of the threaded parts from the barrel. The subject matter herein is a continuation-in-part of that of my copending application, Serial No, 628,046, titled, Turn- 5 Claims. (Cl` 287-60) barrel connections and led November 13, 1945,

which became abandoned June 20, 1947. More specifically, the invention resides in a lock strap which is carried by a barrel and which holds it non-rotatably with respect to the elements Secured thereto so as to prevent unintended rotation and separation.

As used hereinV the term turnbarrel or barrel refers tothe oppositely threaded portion of a turnbuckle intermediate the joined terminal portions.

Turnbarrels have long been used to connect two aligned Wires or rods at their adjacent ends. The turnbarrel is usually interiorly threaded at each of its ends with threads which are so related that the rotation of thebarrel in one direction causes the simultaneousV advance or retreat 'of the threaded ends of the attached elements. n vIn those instances in which a rod of relativelylarge'diameter is used, the end of the rod itself may be threaded and screwed into the turnbarrel. Where rods of small size or wires are to be connected,` they are fixed to connectors which are provided with threaded ends adapted to screw into the turnbarrel.

Some turnbuckles are constructed with only one threaded terminal portion, the other being joined to the barrel with a swivel joint to permit relative rotation.

- Such constructions are old and well known and have been used extensively in many elds andparticularly in airplanes where they perform the very important function of adjusting the length of control cables. On a large airplane as many as two hundred and fifty such connections may be used and, through their ability to draw the cables together, also serve as tension-adjusting means.

As used in airplanes, the turnbarrels usually connect cables which vary in size up to a maximum of about 1/4 inch diameter. 'Ihese cables are initially tensioned with a pull thatrmay vary between fty and one hundred pounds and the turnbarrels and their connections must be at least as strong as the cables which they connect. In the use of these turnbarrels in many places the problem of preventing their unscrewing and loosening due to vibration is a serious one which has received considerable attention. In aeronautical uses, small diameter safety wires are usually threaded through the turnbarrel and through the terminal elements connected thereto in such manner as to prevent relative rotation. These wires are usually twisted between their points of vconnection to the various elements to provide maximum strength. Such locking means, however, have the inherent disadvantage that they require appreciable time to install and are exceedingly difficult to remove or inspect where the space is limited. In many instances periodic adjustment of the turnbuckle is desired and in such cases the safety wire must be removed and discarded and a new wire installed after the adjustment has been made.` In certain parts of an airplane, in which turnbarrel connections are to be found, the available room is very small and is it difficult for the mechanic to crawl into the space and position the locking wire. Under such circumstances, human error and fatigue have produced unsatisfactory results.

In the turnbuckle connection constructed in accordance with the present invention, a simple and economically produced structure is provided which has maximum strength and which positively prevents unintended separation of the parts. The device is easily positioned and when once connected cannot become dislocated as a result of vibration or other exterior forces acting upon the turnbarrel or upon the cables, wires, or rods.

' Accordingly it is an object of the present invention to provide a new and improved turnbarrel connection. p

It is another object of the invention to provide new and improved locking means in a turnbarrel connection.

A further object of the invention is to provide a simple and strong locking element -for a turnbarrel connection which is easily positioned and secured and which cannot be dislocated by vibration. Y

It is another object of my invention to provide a locking element which will permit adjustment or" the turnbuckle to which it is attached without destroyingthe locking element or rendering it ineiective.

A still further object of the invention is to provide locking means for a turnbarrel connection which positively prevents the relative rotation of the connected parts of the turnbarrel while positioned in its place.

These andv other more specii'lc objects will appear upon reading the following specification and claims and upon' considering in .connection therewith the attached drawings to which they relate.

Referring now to the drawings, Figure 1 is a top plan view of a turnbarrel connection constructed in accordance with the present invention;

Figure 2 is a side elevation of the construction shown in Fig. 1;

Figure 3 is an exploded view with the lock strap removed from the turnbarrel which is itself shown in section and with the threaded swedge elements spaced therefrom;

Figure 4 is an elevational section taken on theline 4-4 in Fig 2;

Figure 5 is a partial perspective view of the end of the locking strap illustrated in thefore-` going iigures; and

Figure 6 is a perspective view of the end of a modiiied lock strap.

The reference character I'U in the drawings indicates thev :barrel of a turnbuckle of a common and well known design formed with a longitudinallyextending central passageway II oppositely threaded upon opposite sides of its midpoint, as indicated at I2 and I3. The turn-barrel IBI is provided with a central enlarged portion through whichV extends a transverse passageway It for a reason which will be explained.

Threaded into the threaded ends I2 and' |13 ofi the'barrel are the exteriorly threaded ends I5 and 16 of connectorsor swedge elements Il and I8 which are provided at their outer ends with longitudinally extending cable-receiving bores or cavitiesv I3 and 2t adapted to seat xedly and nonremovably'the ends of the cables 2 I and 22 which are to be secured together. The cables may lbe secured within the-cavities I9 and 20 in any suitable manner whichwill` positively preventl separation. A preferred method is to crimp or swedge the connectors I? and I8- upon thev cables by the use of tremendous pressure.

Positioned upon connectors I'I and I8 between the ends thereof is a nut-like portion indicated by the reference characters 23r and 24. respectively'. These nut-like portions are formed integrally in the connectors Il and I'8 and in a preferred design may be hexagonal although it is to be understood that the exa-ct number of faces' is not' important so long as there are parallel faces upon the opposite sides of the nut-like portion and they have an appreciable surface. In addition totheir function, which will be hereinafter fully set forth; these nut-like portions provide means by which the connectors can. be held non-rotatably as the turnbarrel It is rotated to advance the threaded ends I5 and l5 toward each other to-tension the cables.

According to the present invention, a lock strap 2.6 is4 provided which comprises an elongated, slightly curved strap-like body which gives the element its name. The body is formedv in its extremities with upturned anges to form seats 2'? and 23, the sides of whicharespaced a distance equal to or slightly less than the distance separating` diametrically opposed parallel faces of the nut-like portions 23 and 24. As canbe seen best in Figs. 5 and 6 the seats 21 and 28 are similar in shape and operation to an open end wrench and are installed onto the nut-like portions 23 and 25'; from the side in the same manner as such a wrench would be.

An opening is provided in the central' portion ofthe strap 25 and is so positioned as to align with the passageway I4 whenthe strap isfin place onithe turnbuckle.. Whenthe-v strap; is inlplace as just described, it is secured to the barrel by means of a bolt or pin 29 which is passed through the aligned openings in the strap 26 and the barrel I0.

In order to further secure the lock strap 26 to the turnbuckle, two pairs of spring clips 35 and 36 are formed in the strap 26, one pair adjacent the inner end of each of the seats 21 and 28. As can be seen best in Figs. 1 and 2 these clips 35 and 36 are positioned and adapted to snap over a necked down circular portion of the connectors I1 and I8. The strap 26 being formed of a relatively resilient material, the spring action of the clips 351- andf 36 securely grips the connectors I'I and I8 and holds the seats 2'I and 28 in secure engagement with the nut-like portions 23 and 24. Thus. the strapV is held securely onto the turn- ;buckle and relative rotation of any of the three parts: Il'l, I0 or I8 is prevented by the cooperative action of the seats 2 and 28 and the securing The securing pin 29 may-be in the form of a clevis pin such as that illustrated in the draw.- ings-` and secured in place by means of a cotter key 32- or alternately a common bolt may be used and anut provided to hold the polt in place.

It is' to be noted that by removing the pin 29 but, leaving the strap 26 in place, the barrel I0 may be rotated while holding the connectors I'I and I8'against rotation.

Thus it is possible by removing a single simple par-t, the pin 29; toadjust the tension eiected'by the turnbuckle. When such adjustment: has been made,- the pin maybe reinserted and securedV in place thus lockingA the barrel against further rotation.

The seats 2l and 28 being of considerable longitudina-lextent. permit full adjustment of the turnbuckle without advancing the nut-likev portions 23 and 24 beyond the limit of the seats 2l andiZ. Similarly sufficient length of the necked clown portion of the end pieces I'I and It is provided' to permit relative longitudinal movement between the clips 35 and 33 and the end portions |11" and I8.

In some instances where the turnbuckle is to besubjected to relatively low torque, the securing clips 35and36.may be dispensed with. In Fig. 6 I have illustrated the appearance of the end of a locking strap without' theclip 35.

While the particular apparatus herein shown and described in detail is fully capable of attaining the objects and providing the advantages herei-nbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiment of the invention and the invention isy not limitedto the details'of construction or des-ign'herein other than as defined in the appended claims- I- clairnf:

1.-.. aA turnbuckle, a turnbarrel threaded inf'- teriorly.` at its opposite ends and` formedv with a transverse passageway, exteriorly threaded elementsscrewthreaded into the ends of said turnbarrel andy formed with polygonal surfaces, and locking means seating against and holding said polygonal surfaces against rotation, said locking means includingy a member extended through said transverse passageway, and resilient means adapted to be snappedv onto, and grip said elements-whereby to maintain said seating thereof.

2. In aturnbuck-le, a turnbarrelthreaded interiorlyat its. opposite ends and formedl with a centrally located transverse passageway, connec tors engaged. insaid; turnbarrel, threaded attheir ends and formed with nut-like surfaces spaced from said ends, and a lock strap formed at its ends with seats for holding said nut-like surfaces non-rotatably and having intermediate its ends a bolil extended through the transverse passage way of said turnbarrel, and resilient means formed in said strap adapted to be snapped onto, and grip said connectors and hold said seats against said surfaces.

3. In a turnbuckle, a turnbarrel threaded interiorly at its opposite ends and formed with a centrally located transverse passageway, connectors each formed with recessed cable-receiving ends and with opposite screwthreaded ends engaged in said turnbarrel, each of said connectors being formed within its length with a polygonally sectioned portion having diametrically opposed parallel faces, and locking means to prevent unintended relative rotation of said turnbarrel and connectors comprising a body extended between said polygonally sectioned portions of said connectors and forzned with seats having parallel sides non-rotatably seating against said portions, a bolt extending from said body through said passageway; and a pair of resilient jaws formed in said body adjacent each of said seats adapted to be snapped onto said connector from a side thereof whereby to grip said connectors and hold said seats thereagainst.

4. A locking strap for a turnbuckle comprising an elongated strap having a transverse central opening, end-wrench-like ends formed therein adapted to engage and non-rotatably hold terminal members of said turnbuckle, spring clip means formed adjacent each ofsaid ends adapted to be snapped onto said terminal members from a side thereof whereby to grip said terminals and hold said wrench-like ends in said engagement;

and a transversely disposed pin in said opening i a cylindrical necked down portion and a polygonal nut-like portion adjacent thereto, a locking meniber comprising in combination: an elongated strap portion adapted to be non-rotatably secured to said barrel and extend longitudinally parallel to said turnbuckle; a pair of end-wrenchlike seats formed in the ends of said strap portion, said seats being positioned and adapted for en* gagernent with said nut-like portions by application from the side of said tul'nbuclle; anda pair of spring clips, one adjacent each of said seats, each of said clips comprising a pair of resilient jaw members adapted to snap over and grip said necked down portion upon said application of said seats whereby to retain said seats on said nut-1ike portion.

ROBERT W. LANDON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

